Red azo dye and process of making same.



UNITED STATES PATENT OFFICE;

ADOLF ISRAEL AND RICHARD KOTHE, OF ELBERFELD, GERMANY, ASSIGNORS TO FARBENFABRIKEN OF ELBERFELD 00., OF NEW YORK, N. Y.

RED AZO DY E AND PROCESS OF MAKING SAME.

SREGIEICATIQN forming part of Letters Patent No. 677,516, dated July 2, 1901.

Application filed February 25, 1901. Serial No, 48,739. (Specimens.)

To aZZ whom it may concern:

Be it known that we, ADOLF ISRAEL and RICHARD KOTHE,doctors of philosophy,chemists, (assignors to the FARBENFABRIKEN OF ELBERFELD COMPANY, of New York,) residing at Elberfeld, Germany, have invented a new and useful Improvement in Red Azo Dye and Process of Making Same; and we hereby declare the following to be a clear and exact description of our invention.

In two applications for Letters Patent filed February 20, 1901, and bearing Serial Nos. e8,l67 and 48,168, we have described the production of new simple or mixed guanidin derivatives of amidonaphthol sulfonic acids which have the following general formula:

on on 10 5\X in which formula X means a hydrogen atom which can be replaced by a sulfonic group and which can be produced by treating the thio-urea compounds of amidonaphthol sulfonic acids having the formula:

with amidonaphthols or amidonaphthol sulfonic acids (such as beta,-amido-alpha -naph thol, beta -amido-beta naphthol, beta -amidoa]pha -naphthol-betrm-sulfonic acid, alpha amido-alpha -naphtholbeta -sulfonic acid, beta -amido-alpha naphthol beta sulfonic acid, or the like) in the presence of agents capable of absorbing sulfureted hydrogen, such as lead oxid or the like.

Our present invention relates to the production of valuable new azo coloring-matters by causing three molecules of either the same or different diazo compounds to act on the said guanidin derivatives.

WVe point out specifically that by the term diazo compound in the following specification we intend to denote a simple diazo compound as well as a diazotized amidoazo compound, such as diazoazobenzene, diazoazotoluene, or the like.

The new azo dyestuffs are alkaline salts of acids having the following general formula:

on l I=N-X 5; in which formula X-N=N mean radicals of either the same or different diazo compounds, y' means a hydrogen atom which can be replaced'by a sulfonic group and which are from reddish-brown to dark-brown pow- 6o ders soluble in water with from orange to bluishred color. They dye unmordanted cotton from orange to bluish-red shades.

in carrying out our new process practically we can proceed as follows, the parts being by 6 5 weight: 36.3 parts of para-xylidin are diazotized in the usual manner with the aid of one hundred and eighteen parts of hydrochloric acid (of 15 Baum) and twenty-one parts of sodium nitrite. The resulting diazo solution 70 is then slowly stirred into a solution prepared from 72.5 parts of the guanidin derivative, (prepared from the thio-urea compound of beta -amido-alpha naphthol beta sulfonic acid and beta -amido-alpha -naphthol-betansulfonic acid,) having in a free state theformula:

and one hundred and sixty-eight parts of sodium carbonate, (N21 GO After having stirred for several hours the formation of the dyestuff will be finished. The latter is separated from the mixture by the addition of common salt and isolated by filtration. The new coloring-matter thus obtained is the sodium salt of an acid having in a free state most probably the following formula: 10o

and is a reddish-brown powder having a metallic luster soluble in water with a red color. It is insoluble in concentrated hydrochloric acid, while it is dissolved by concentrated sulfuric acid (of 66 Baum) with a bluish-red color, which is not changed on the addition of a small quantity of ice, while on the addi- 1 tion of a larger quantity of ice a dark-brown precipitate is obtained.

The new coloring-matter dyes unm ordante'd cotton red shades.

The process proceeds in an analogous manner, if instead of the diazo compound mentioned in the example other diazo compounds 'are employed. On using, for instance, one molec ule of beta-napht-hylamin and two mole- 3 cules of ortho-anisidin or one molecule of amidoazo' benzene', one molecule of beta-naphthylamin, and one molecule of parateluidin I bluish-red dyestulfs are obtained.

Having now described our invention and in what manner the same is to be performed, what we claim as new, and desire to secure by Letters Patent, is

1. The process for producing new 2120' dye= stuifs which process consists in combining three molecules of diazo compounds with one molecule of the herein-defined guanidin derivatives having in a free state the general in" which formula X means a; hydrogen atom which may be replaced by a sulfonic group then precipitating the resulting dyestufis by means of a suitable salt and finally isolating the same from the reaction mixture, substantially as hereinbefore described.

2. The process for producing a new trisazo dyestnff which process consists in first combining three molecules of diazotized parawhich in the form of its sodium salt is a reddish-brown powder having a metallic luster, soluble in water with a red color, insoluble in concentrated hydrochloric acid, being d'i'ssolved by concentrated sulfuric acid of 66 xylidin with one molecule of the guanidin 5 derivative obtained from the thio-urea compound of beta -amido-alpha -naphthol-beta gSlllfODlC acid and from beta,-arnido-alpha -naphthol-beta -si1lfonic acid having the folwith the aid of a suitable salt, and finally isolating the same from the reaction mixture,

. which are alkaline salts of acids having most scribed.

Baum with bluish-red color which isnot changed on the addition of a small quantity of ice, while on the addition of a larger 2 quantity of ice a dark-brown precipitate is i obtained, dyeing unmordanted cotton red 3 scribed.

substantially as nerelnbefere described, I

The herein-described new azo dyestuffs 7o probably the following formula:

I OH m in which formula X-eNi N and y have the herein-defined meaning, and which are from reddish-brown to dark-brown powders-having 80 a metallic luster, soluble in water with from orange to bluish-red color and dyeing unmordanted cotton from orange to bluishred shades, substantially as her'einbefore de= 8 4%. The herein-described new trisazo dyestu-if being an alkalinesalt of an acid having most probably the following formula:

shades, substantially as herei-nb'et'ore de 100 In testimony whereof we have signed our names' in the presence of two subscribing witnes'ses. V 7

ADOLF ISRAEL; RICHARD KOTHEl WVitnesses:

OTTO Ket le,- EMIL BLOMBERG. 

